:root {
  --primary: #0077b6;
  --primary-dark: #005f86;
  --light: #caf0f8;
  --text: #333;
  --danger: #e63946;
}

body {
  font-family: 'Noto Sans JP', sans-serif;
  background: linear-gradient(135deg, var(--light), #e0f7fa);
  color: var(--text);
  min-height: 100vh;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 20px;
}

.navbar {
  background: var(--primary);
  color: white;
  padding: 16px 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.navbar .logo {
  font-size: 1.8rem;
  font-weight: 700;
}

.navbar .user-info {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 500;
}

.streak {
  background: white;
  color: var(--primary);
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: 600;
}

.btn {
  padding: 12px 20px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 500;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn:hover {
  background: var(--primary-dark);
  color: white;
}

.form-group {
  margin-bottom: 20px;
}

label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
  color: #03045e;
}

input {
  width: 100%;
  padding: 14px;
  border: 1px solid #ddd;
  border-radius: 12px;
  font-size: 1rem;
}

input:focus {
  border-color: var(--primary);
  outline: none;
  box-shadow: 0 0 0 3px rgba(0, 119, 182, 0.2);
}

.error-message {
  color: var(--danger);
  margin: 10px 0;
  font-weight: 500;
}